Porous Bodies and Methods

ABSTRACT

Systems and methods for treating a fluid with a body are disclosed. Various aspects involve treating a fluid with a porous body. In select embodiments, a body comprises ash particles, and the ash particles used to form the body may be selected based on their providing one or more desired properties for a given treatment. Various bodies provide for the reaction and/or removal of a substance in a fluid, often using a porous body comprised of ash particles. Computer-operable methods for matching a source material to an application are disclosed. Certain aspects feature a porous body comprised of ash particles, the ash particles have a particle size distribution and interparticle connectivity that creates a plurality of pores having a pore size distribution and pore connectivity, and the pore size distribution and pore connectivity are such that a first fluid may substantially penetrate the pores.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation and claims the priority benefit ofU.S. patent application Ser. No. 12/183,917, filed Jul. 31, 2008, whichclaims the priority benefit of U.S. provisional patent application No.60/963,088, filed Aug. 3, 2007, the disclosures of which areincorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates generally to reacting a fluid with a body,and more particularly to a body for reacting with a fluid.

2. Description of Related Art

Fluids (e.g., gases, liquids and the like) may be passed over or througha variety of substances in order to facilitate a reaction. The reactionof species in the fluid, the removal of species from the fluid, and theconversion of the fluid in some chemical or physical fashion may beenhanced by contacting the fluid with a suitable body. In some cases,reactions occur at the interface between the fluid and a surface of thebody, and in such cases, it may be advantageous to maximize this surfacearea (e.g., by using a porous body). Reactions between a fluid and abody may also be used to modify the body itself.

Many suitable bodies are substantially porous (e.g., over 5%, 10%, 20%,40%, 60%, 80%, or even over 90% porous). Porosity may be continuous, andin such cases, the fluid may substantially saturate the body. Whenpushed by a suitable driving force (e.g., pressure, voltage, magneticfield or other gradient in thermodynamic potential) a fluid may becaused to pass through the body. In some cases, a species may be removedfrom a fluid by passing the fluid through pores that block the passageof the species (e.g., filtration). In other cases, a species may beremoved or reacted to form another species (e.g., in heterogeneouscatalysis) and/or combine with the body per se (e.g., gettering). Aspecies may also be substantially adsorbed or absorbed by the body.

Many bodies have been fabricated by choosing relatively pure startingmaterials and mixing them, and increasingly complex bodies require theaddition of more starting materials. For example, a catalytic convertersubstrate may be required to have certain thermal, mechanical, andsurface area properties, so might be made of cordierite (Mg₂Al₄Si₅O₁₈),which may be made by mixing MgO, Al2O3 and SiO2 starting materials.Cordierite containing iron (Mg,Fe)₂Al₄Si_(s)O₁₈ may have some improvedproperties, and might be made by adding FeO or Fe₂O₃ to theaforementioned mixture. Sintering aids, grain boundary phases, andcatalytic species could be similarly added, and improvements to manymaterials generally entail the addition of further components.

Many useful bodies, particularly bodies for high temperatureapplications, include several components, and in some cases, additionalcomponents may improve properties. For example, mullite (3Al₂O₃-2SiO₂)materials often have high strength at fairly high temperatures (e.g.,1300 C), and U.S. Pat. No. 3,954,672 identifies certaincordierite-mullite compositions (i.e., of increased complexity) thathave some improved properties over mullite. As such, materials havinggenerally improved properties in an application may often be morecomplex than known materials typically used in the application.

Many useful bodies are fabricated from combinations of SiO₂, Al₂O₃, FeO,MgO, CaO, TiO₂ and other materials, and often include one or more usefulphases (e.g., mullite, cordierite, spinels, perovskites, amorphous),each of which may include several components. Thus, the discovery ofimproved bodies for a variety of applications might be enhanced bybasing those bodies on compositions known to have useful properties,then increasing complexity around these compositions.

Porous bodies may be used for filtration, including without limitationdeep bed filtration, wall flow filtration, cake filtration, and othermethods. Generally, an appropriate body for use in filtration may bechosen based upon a variety of factors, including required flow rates,viscosity of the fluid, phase assemblage of the fluid (e.g., suspendedsolids in a liquid, emulsions), concentration of species (to be treated)in the fluid, desired pressure differential (if pressure is driving thefluid through/past a body), temperature of the application, chemicalreactivity (or lack thereof) and other factors. Available geometricaland mass constraints may also determine an appropriate filtrationmethod. For example, large “ponds” of deep bed filtration bodies may beused to filter large amounts of wastewater, whereas catalytic removal ofcontaminants in an automotive exhaust gas stream may require a small,portable body.

In some applications, the mechanical behavior of the body may beimportant. Often, the driving force used to cause a fluid to passthrough or past a body creates a mechanical stress in the body itself,and the body's resistance to this mechanical stress is a requirement inmany applications. Some applications require that a body have sufficientmechanical strength to withstand an applied pressure exerted by thefluid (e.g., in a filter). Some applications may require a low thermalexpansion coefficient (CTE), good thermal shock resistance, or goodthermal shock damage resistance.

In many applications, channels or other substantially “open” regions ofthe body (offering minimal impedance to fluid flow) are used tosubstantially increase area for reaction or filtration (for example, asin U.S. Pat. Nos. 4,253,992 and 4,276,071). In such applications,relatively thin walls separate regions having substantially minimalimpedance to fluid flow. Walls separating the channels should have bothhigh porosity to maximize surface area or permeability, but not so highporosity that mechanical properties are degraded, and the pore sizedistribution should provide for the desired treatment (e.g., actuallyfilter the species being removed).

In some applications (e.g., a filter bed) a body may be essentiallyhydrostatically supported during operation, and so require littlemechanical strength (e.g., shear or tensile strength) during filtration.Some applications also include backwashing, which often creates adifferent mechanical stress than that created during filtration. In suchinstances, some mechanical strength or appropriate containment may benecessary. Thermal stresses, thermal expansion mismatch, changes incrystallographic structure, physical impact, and other factors may alsocreate certain requirements of a body in a given application.

Increasingly, cost may be an important factor in a given application.Costs may include capital costs associated with fabricating the body andassociated fluid control system itself. Cost may also includeoperational costs. Costs may also include disposal costs, environmentalcosts, “cradle to grave” costs and other costs associated withimplementing a particular treatment solution. The energy required tocreate and implement a particular body may be an important cost factor,and in such cases, reducing the energy required to make and use aparticular device may be advantageous. Cost may include a costassociated with emitting global warming gases, environmental pollutants,or other contaminants. Often, minimizing the embodied energy associatedwith a product (e.g., the energy required to create and implement theproduct) and/or minimizing a total lifecycle cost of the product may beadvantageous. The implementation associated with a treatment method, themethod of treating the fluid with the body, the disposal of treatedsubstances and/or the body itself, and other lifecycle costs maygenerally include both capital costs (including raw materials costs),operational costs (including lifetime) and disposal/recycling costs.

SUMMARY OF THE INVENTION

Systems and methods for treating a fluid with a body are disclosed.Various aspects involve treating a fluid with a porous body. Certainaspects include a system for reacting fluid with a body. The systemincludes a container having an inlet and an outlet, and a body withinthe container comprised of ash particles. The body may have sufficientporosity that the fluid reacts with the body during passage from theinlet to the outlet (i.e., through the container). In some cases, thebody may be disposed in the container such that the first fluid mustpass through the body during passage from the inlet to the outlet, and apore size distribution and a pore connectivity may be configured toallow the first fluid to pass through the portion of the body sodisposed. Some bodies may be filters. Various bodies include catalyststo increase a rate of a chemical reaction. Some bodies have porosityranging from 4 to 98%. Some bodies include channels, through which afluid may pass substantially unimpeded. Some channels may passcompletely through the body (e.g., from a first side of the body nearthe inlet to a second side of the body near the outlet).

Porosity may include a pore size distribution, and may at leastpartially result from the removal of a fugitive phase. A fugitive phasemay be provided intrinsically, as a residue associated with an ashsource. A fugitive phase may be added separately. Some bodies compriseloose particles. Other bodies include bonded particles, and in somecases, bonding includes necks between particles. Necks may be formedfrom cementitious bonding, which may include hydration reactions amongoxide components (e.g., Ca, Si, P, Mg, Fe, Al, and other oxides), andmay include the formation of C₃S, C₂S, C₃A, C₄AF, phosphates and/orgypsum phases. Neck formation may include sintering and/or other hightemperature reactions.

Methods provide for using various bodies to treat a fluid. In somecases, a fluid may be an exhaust gas, which may include substances suchas hydrocarbons, NOx, CO, Hg, sulfur species, and/or particulate matter.Liquids, including liquid metals, may be filtered.

Various methods include selecting an application for which a porous bodyis required, selecting an ash source with which to fabricate the body,and forming the ash source into a porous body for the application. Oneor more subsets of various particle size distributions may be selected.Certain embodiments include filter beds comprised of ash particles.

Matching an ash source to an application may include the determinationof an application vector describing the application, calculating atarget body vector that describes an appropriate body for theapplication, selecting a source material (which may include an ashsource), calculating a body vector based on the source material, andcomparing the calculated body vector to the target body vector. In somecases, various parameters are adjusted iteratively until the calculatedand target body vectors achieve a quality of matching or fitting to eachother. Body parameters and application parameters may be adjusted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic representation of an exemplary embodiment.

FIG. 2 is a diagrammatic representation of an exemplary embodiment.

FIG. 3 is a diagrammatic representation of an exemplary embodiment.

FIG. 4 provides a diagrammatic representation of a representativesection of a channel embodiment.

FIG. 5 is a diagrammatic representation showing an alternating channeldesign according to certain disclosed embodiments.

FIG. 6 is a diagrammatic representation of an exemplary embodiment.

FIG. 7 is diagrammatic representation of an exemplary embodiment.

FIG. 8 is a flowchart of a process according to certain embodiments.

FIG. 9 shows particle size and composition information for an exemplaryash source, according to certain embodiments.

FIG. 10 shows particle size and composition information for anotherexemplary ash source.

FIG. 11 shows particles size information for an additional exemplary ashsource, according to certain embodiments.

FIG. 12 shows particles size information for an additional exemplary ashsource, according to certain embodiments.

FIG. 13 shows two cross sectional electron micrographs of a Sample 1 atdifferent magnifications, according to certain embodiments.

FIG. 14 shows pore size information associated with several exemplarybodies, according to certain embodiments.

FIG. 15 shows pore size information associated with several exemplarybodies, according to certain embodiments.

FIG. 16 shows pore size information associated with several exemplarybodies, according to certain embodiments.

FIG. 17 shows CPET (cumulative percent finer than) data describing theporosity of several fired samples.

FIG. 18 is a plot of average porosity vs. median pore diameter forseveral bodies, according to certain embodiments.

DETAILED DESCRIPTION OF THE INVENTION

A fluid may be treated with a porous body. In select implementations, abody comprises ash particles, and the ash particles used to form thebody may be selected based on their providing one or more desiredproperties for a given treatment. Treatment typically occurs in thecontext of an application or process directed toward interacting a fluidand the body. Fluids may refer to gases, liquids, and mixtures thereof.Fluids may include several components, and in some cases, a fluidincludes discrete solid and/or liquid phases (e.g., a smoke or mist). Atreatment or application may include the reaction, removal, and/ortransformation of a substance or species in the fluid and/or the body.The substance or species may be a solid, a liquid, a gas, a solute oreven the fluid itself. Ash particles generally include substantiallyinorganic species, often resulting from a high temperature process.Generally, ash particles may be associated with (e.g., resulting from) acombustion process, and so may include oxides. Body generally refers toan object comprised of a plurality of particles. A body may includeobjects that were fabricated from particles, notwithstanding that thebody (post-fabrication) may not be considered “particulate” per se.Porous generally describes a body having at least some (e.g., greaterthan 1%) porosity. Various embodiments include identifying a body thathas appropriate characteristics for an application, and in some cases, abody may be fabricated from low cost materials.

Given an application in which a fluid is passed through or over a porousbody to effect a reaction or removal of a substance or species, avariety of references exist with which a user may determine a set ofdesired characteristics of the body. Exemplary texts include Rules ofThumb for Chemical Engineers (C. R. Branan, Gulf ProfessionalPublishing), Perry's Chemical Engineer's Handbook (D. W. Green & R. H.Perry, McGraw-Hill; Transport Phenomena (Bird, Stewart & Lightfoot,Wiley). Application characteristics such as desired flow rate, fluidcomposition, geometry of an interaction system, pressure drop and thelike may be used to define an application vector that may includedesirable properties of a body for that application. This vector may bea target, toward which a body having a set of body characteristics maybe directed. Various models may be used to calculate macroscopic bodycharacteristics using microscopic parameters such as particle size,porosity, density and pore size distribution. Similarly, referencesteaching the enhancement of chemical reactions (e.g. catalysis on thesurfaces of the body) may be used to provide for desired chemicalreactions in a given application, and other references may teachprocessing methods (to make the body), ways to improve mechanicalproperties, methods to clean, and the like. Many reactions may beenabled by a catalyst, and an appropriate catalyst choice may be aneffective way to use a “generic” substrate for a wide range of reactionsby choosing a catalyst or catalytic condition appropriate for thereaction and incorporating it into, onto or with the substrate.

Some reactions involving a fluid and a porous body may entail immersingthe body in the fluid and allowing for reaction via diffusion into thebody or passage over a surface of the body. A stream of fluid may bepassed over, around, among members of, or through a body, and a body maybe solid, a powder, a fluidized bed, or other set or particles. Somebodies may be substantially solid, such as a catalytic convertersubstrate. Other bodies may be mechanically weak, such as a fluidizedbed, and may be disposed in a container and/or with suitable packaging.Some bodies may be formed in-situ, such as a so-called cake layer formedby the deposition of material on a “sub filter” substrate during passageof the fluid. In such cases, filtration may improve with time asfiltration increasingly results from filtration through the cake layer.

Treatment may include cold temperatures (e.g., 77 K or below), moderatetemperatures (e.g., room temperature), high temperatures (e.g., above700 C, 1000 C, 1300 C, or even 1600 C) and temperatures in between.Reactions may include filtration, conversion of one or more species, gasadsorption, desulfurization, de-NOx reactions, removal of hydrocarbons,Hg, CO, and other chemical reactions. Treatment may include the removalof particles or particulates from the fluid, including the removal ofsoot particles from an exhaust stream, or the removal of contaminantsfrom a liquid metal. Treatment may include water purification. In someapplications, treatment includes an interaction between a fluid and abody for the purpose of modifying the body, rather than the fluid.

Bodies and/or fluids may include means to catalyze a reaction. Suchmeans can include a catalyst disposed on a surface of the body, surfacesof the particles, in the fluid, a particular surface treatment orcondition associated with the body, and/or combinations thereof.Catalysts may include Group VIII metals, Pt-group metals, rare earthoxides, oxides of Fe, Ni, Co, Mn, Cr, W, Mo, V, Nb, Ta, Re, Cu andmixtures thereof. For example, it may be advantageous to catalyze thedecomposition of NOx, the combustion of CO and/or hydrocarbons, thecombustion of soot particulates, and other high temperature gas phasereactions by choosing an appropriate catalyst. Catalysts may include Ce,Zr, Ti, Ba, Sr, Ca and/or oxides thereof, including zeolites andmesoporous materials. Catalysts may include sulfides, particularlytransition metal or rare earth sulfides. Catalysts may includeheterogeneous or homogeneous catalysts. In some aspects, catalysts areorganic and/or organometallic. Wash coating a catalyst may be used toapply a catalyst to a body. A catalyst may also be dispersed ordissolved in a fluid and deposited on the body by filtering the catalystfrom the fluid with the body. In some aspects, a catalyst is added tothe fluid being treated.

An application may have a plurality of characteristics definingchemical, physical, thermal, temporal and other characteristics of theapplication. Typical characteristics include a fluid to be treated,viscosity, a substance to be reacted or removed, temperature, pressure,flow rate, chemical reactivity requirements (both enhancing desiredreaction and preventing undesired reactions), lifetime, and factors suchas physical plant requirements (e.g., mass, size, density, shape,resistance to damage) of the porous body and associated componentsthemselves. For a given application, an application vector describingvarious important factors may be created. An application vector mightinclude input descriptors (e.g., the fluid to be treated) and outputdescriptors (e.g., a maximum concentration of a species in the treatedfluid). Various components contributing to cost of the application mayalso be included, such as raw materials cost, fabrication cost,installation cost, replacement cost, process cost, and disposal cost.Certain characteristics may be particularly important with respect to aparticular application. Size and weight may be more important for amobile application than for a stationary application. Lifetime may bemore important for a remote application than for an easily accessibleapplication. “Fault tolerance” or “failsafe” requirements may be moreimportant for an application in which failure is intolerable (e.g., abackup electrical generator at a hospital or data center), but less sowhen failure has modest consequences. Knowledge of an application may becaptured in an application vector, and may be used to identify preferredvalues for a body used in the application.

Given an application vector or other descriptor of an application, atarget body vector may be determined, which describes the desiredfeatures of a body to be used in the application. Exemplary featuresinclude macroscopic features (size, weight, surface area, permeability,coefficient of thermal expansion, moduli, heat capacity, thermalconductivity), microscopic features (porosity, pore shape, pore sizedistribution), chemical reactivity, catalytic requirements, and otherfactors. In some aspects, a diverse set of source materials andprocessing conditions are evaluated, a body vector is calculated foreach member of the set, and the body vectors are compared to a targetbody vector for an application to find a preferred body vector.Experimental data may be incorporated into evaluation. In some aspects,the composition, phase assemblage, and particle size distribution of anash source may be used to associate an ash source with desiredproperties of a body, and by extension, with an application.

For example, treatment of diesel exhaust may be characterized in termsof an application vector comprising flow rates, temperatures, maximumbackpressure, lifetime, and other factors. A diesel particulate filtermay comprise a porous body having a body vector (e.g., size, weight,permeability, temperature range) that provides for the body's use in theapplication. In some aspects, components of the body (e.g., composition,particle size, forming method) may be used to calculate a body vector,and a calculated body vector may be matched to a target body vector(from the application). Thus, a diesel particulate filter applicationmay require a body having a certain permeability, which may be used tocalculate a combination of physical factors (e.g., wall thickness) andporosity (e.g., 40-70% porosity, a pore size distribution spanning 10-40microns, and a mean pore size of 25 microns) expected to provide for anappropriate body. By incorporating source particle data (e.g., particlesizes) and particle packing models, a hypothetical porosity, pore sizedistribution and mean pore size may be calculated. By changing inputparameters (e.g., amounts of different particle sizes), the calculatedporosity may be iterated toward the target porosity. Varioushypothetical compositions may be used as experimental starting pointsfor fabricating bodies.

Ash sources may be diverse in chemical composition, phase assemblage,LOI (loss on ignition), particle size, and other factors. Ash particlesmay range from below 100 nm to above 1 cm in size. In select aspects,ash particles range from about 1 micron to about 70 microns in size. Insome cases, larger ash particles (e.g., above 20 microns) may be used toincorporate larger pore sizes, and smaller ash particles (e.g., below 5microns) may be used to incorporate smaller pore sizes. In certaincases, a body contains regions having different sized particles, andeach region provides a complementary feature. In some examples, a firstregion provides structural properties and a second region provides fluidtreatment properties. In certain embodiments, small particles providefluid treatment properties, and larger particles support the smallerparticles. Various embodiments include first particles providingmechanical properties and second particles providing high surface area(e.g., over 30 m̂2/g).

In many cases, ash particles may also include a substantial amount(e.g., greater than 1%, 10%, 30%, 40%, 50%, or even greater than 60%) ofan organic or other carbonaceous species. Many combustion processes donot result in complete combustion of the fuel source, and so resultingash particles may be associated with one or more “partially combusted”or “uncombusted” organic species. For many ash materials, the relativepercentage of inorganic to carbonaceous species may be characterizedusing LOI, corresponding approximately to the amount of carbonaceousspecies removed from the as-produced ash material during a subsequentcomplete firing of the material in an oxidative atmosphere. Exemplarytypes of ash particles may include fly ash, waste incinerator ash,bottom ash, volcanic ash, coal gasification ash, combustion ash, ashfrom biomass combustion or gasification, ash from metallurgicalprocesses, slags and other ashes. Ash particles may generally be anyshape, including but not limited to spherical, spheroidal, angular,platelike, whisker, hollow, cenospheric, fibrous, and other shapes. Ashparticles may comprise Class C fly ash, Class F fly ash, and otherclasses of fly ash.

Ash particles may be obtained from a variety of sources, and thecomposition of the particles is generally a function of the process (andinputs to that process) used to create the ash particles. For example,the combustion of municipal solid waste may create ash particles havingcompositions associated with that particular waste stream (e.g.,household garbage, waste paper, sewage solids, and the like). Coalcombustion may produce a variety of ash sources, including fly ash,bottom ash, boiler slag, flue gas desulfurization ash, gasification ash,and fluidized bed combustion ash. Ashes resulting from combustion may becharacterized by the fuel source, particularly the chemical composition(e.g., sulfur content), geographical location of the source (e.g.,Powder River Basin, Wyo.), coal quality (e.g., lignite, subbituminous,bituminous), and other factors. Ashes may be characterized by theirrespective combustion conditions (e.g., temperature, oxygen partialpressure). Ashes may be characterized by particle size distribution,chemical composition, crystalline and/or amorphous structure,reactivity, LOI, and the like.

Some ash sources from a single combustor and fuel source may include avariety of diverse compositions and phases. For example, Gottschalk et.al. describe ash containing hollow cenospheres, spheroidal magnetiteparticles, silicates, various carbonaceous species, and particles ofvarious shapes, in addition to a range of particle sizes (Ceram. Trans.[119] (2001) 125-134). Other ash sources may be fairly homogeneous. Ashparticles having a diverse range of properties may be obtained, due tothe broad range of processes and inputs creating ash particlesworldwide. Much as the petrochemical industry integrates varyingsupplies and qualities of a raw material (e.g., crude oil) into outputproducts meeting a standardized set of requirements (e.g., gasoline),various embodiments entail obtaining, evaluating, selecting, andoptionally modifying diverse ash sources, selecting one or more subsetsof the sources, forming the selected ash into bodies, and testingproperties to determine a fit for a selected application.

Ashes may include one or more phases having one or more components. Someashes may be substantially crystalline; some ashes may be substantiallyamorphous; some particles may be hollow. Ash particles may be magnetic.Many sources of ash are relatively low cost. In some cases, ashparticles must be otherwise disposed of (if not used in a subsequentapplication), and so the utilization of ash particles (e.g., in anapplication as described herein) may reduce disposal costs. Particlesmay be characterized by a particle shape (or shapes), particle sizedistribution, and interparticle connectivity (e.g., in the body).

A body may be formed, packaged or otherwise contained in a fashion suchthat the fluid may be exposed to the body in a controlled manner. A bodymay have mechanical integrity (e.g., strength, elastic response)sufficient to meet structural requirements of an application. In someembodiments, a body has a tensile strength above 1 MPa, preferably above10 MPa, and more preferably above 100 MPa. A body may include a deep bedof particles, a fixed bed, a fluidized bed, or another assemblage ofparticles. Some bodies include a shear strength above 1 kPa, andpreferably above 10 kPa.

Porosity may refer to closed porosity and/or open porosity. Porosity maybe characterized by a pore size distribution, mean pore size, medianpore size, pore shape, pore connectivity, and other “pore-scale”factors. Porosity in the body may also be characterized with variousmacroscopic factors such as % porosity (e.g., as compared to a densebody of similar composition), permeability, permeation values, surfacearea, and the like.

An application may entail the use of a force during treatment (e.g., amagnetic field that stabilizes or aligns a body comprising magneticparticles). Certain aspects include bodies that have low porosity (e.g.,less than 10%, 5%, 2%) porosity. Other aspects include bodies havingmoderate porosity (e.g., between 10 and 60%). Some embodiments may havehigh porosity (e.g., above 60%, above 70%, above 80%, or even above90%). Various embodiments include bodies having open porosity between 20and 80%, and certain aspects incorporate substantially open regions orchannels or paths, whose incorporation may result in overall densitiesmuch lower than (e.g., 10%, 1%, or even below 0.1% of) a body not havingsuch regions. Relationships between macroscopic factors such aspermeability and microscopic factors such as pore size may becalculated. Pore size distribution may be predicted from a particle sizedistribution (optionally with particle shape data) using standard modelsfor particle packing or using references teaching such relationships.Often, a first characteristic may be calculated, or at least inferred,from a second characteristic. Such data may be used to choose anappropriate ash source from which to fabricate a body for a particularapplication. Various embodiments may be characterized by a specificsurface area, and in some cases, a specific surface area may be greaterthan 10, 100, 1000, 10,000, 100,000, or even 1E6 square inches per gram.Certain embodiments include pores greater than 5 microns in size, andthese pores comprise between 0.1 and 0.8 cm̂/g of a body. A preferredimplementation includes a coefficient of thermal expansion below 8E-6/C,preferably below 4E-6/° C., and more preferably below 2E-6/° C.

Often, porosity characteristics must be optimized among conflictingrequirements, such as permeation rate vs. mechanical properties.Additionally, some processes used to form a body (such as molding,extrusion, slip casting, gel casting, doctor blading, and other formingoperations) require input pastes, slips, or materials having specificviscoelastic properties, which are often affected by the particle sizeddistribution of the associated ash particles and/or an organic binder(which may also affect porosity).

In some embodiments, porosity may be controlled via the use of anappropriate particle size distribution, which may include the use ofsurfactants, stabilizers, stearic moieties (e.g. lipids) and othercompounds that affect or control the interparticle spacing and/orarrangement. Porosity may be controlled by using diverse sets ofcontrolled particle sizes. Porosity may be controlled by a formingoperation, such as an applied pressure, a sintering process, or anetching process. In certain aspects, porosity is at least partiallycontrolled via the introduction of a fugitive phase during forming,which generally affects the particles during a molding or formingprocess. Subsequent to molding, the fugitive phase may be removed,leaving the desired porosity trait.

A fugitive phase may include organic (e.g., hydrocarbons, carbohydrates,graphite) and/or inorganic materials (e.g., ice). A fugitive phase maybe included as discrete particles, as a substantially continuous phase,or as a coating or other adherent phase associated with the particles. Afugitive phase may be a component of the ash particles as produced bythe process yielding the ash (e.g., the residual soot or carbonaceousspecies associated with some fly ashes). A fugitive phase may be addedseparately. Representative fugitive phases include carbon black,starches, and polymers (including polyethylene, polystyrene, polyamides,PET, Polylactic acid, polyvinyl alcohol, and others). Whiskers, fibers,platelets and other anisotropic shapes may also be used as fugitivephases. In some aspects, a fugitive phase may include particles rangingfrom 10 nm-500 microns in size, and some embodiments include fugitivephase ranging from 100 nm to 100 microns in size. Exemplary fugitivephases include graphite particles between 44 and 200 microns, graphiteparticles below 44 microns, and carbon black having mean particle sizesbetween 100 nm and 3 microns. Certain embodiments include large(e.g., >1 mm or even >1 cm) fugitive phases. Fugitive phases may includecellulose, charcoal, coal and other species. Various organic additivesused to control rheology, forming, demolding, and other formationaspects may also be fugitive phases.

Removal of a fugitive phase may include combustion. In certain aspects,heat resulting from this combustion may be used to enhance a firing orother processing step. Gas flow through the body may be used to controlthe combustion of a fugitive phase.

For many applications, a particular ash may provide a “pre-mixed” rawmaterials source having a desirable composition. Thus, a cordierite bodymight be fabricated by choosing an ash already having at least some (andpreferably most) of the elements necessary for forming cordierite.Certain embodiments include matching an ash source, a forming processand an application requiring a body, such that a body formed from theash source according to the process may be appropriate for theapplication.

Ash particles may include substantial amounts of SiO2 and Al2O3. Someashes may also include substantial amounts of Fe species, and other someashes often include Ca, Mg, and other materials. Typically, thesespecies are present as oxides. Often, ash particles will include mixedoxides and/or mixed phases, which are readily identifiable through acombination of chemical (e.g. energy dispersive spectroscopy, x-rayfluorescence, plasma-optical emission spectroscopy, etc.) and physical(x-ray diffraction, particle size analysis, particle shape analysis)methods. In some aspects, an ash having a composition that might beinappropriate for a first application is an excellent choice for asecond application. For illustrative purposes, and without intending tolimit to any particular ash source or application, Table 1 lists severalash source compositions, along with comparable compositions of severaluseful materials.

TABLE 1 Chemical Compositions of Certain Ashes and Certain CeramicsComposition wt % SiO2 wt % Al2O3 wt % MgO wt % Fe2O3 wt % CaO ReferenceCordierite 2MgO—2Al2O3—5SiO2 51 35 14-x x Elk Creek (WV) bituminous ash57 30 1 6.7 1 [1] Pulverized Ohio 5/6/7 blend ash 38 39 1 13 2 [2]Wyodak PRB coal ash 43 17 4 6 23 [2] 3,954,672 Composition B 47 33 13 1[3] 3,954,672 Composition C 43 39 11 1 [3] 3,954,672 Composition E 40 4411 1 [3] MSW Incinerator Ash 18 9 3 2 19 [4] Mullite 3Al2O3—2SiO2 28 72Spinel MgAl2O4 72 28 1: Jung & Schubert, Energy & Fuels (1992)[6],59-68. 2: Seames, Fuel Processing Technology (2003) 109-125. 3: U.S.patent # 3,954,672 4: Cheng et al., Ceram. Int'l. (2002) 779-783.

For example, the composition of the Elk Creek bituminous coal ash inTable 1 is relatively close to the composition of cordierite, andparticularly close to a cordierite that is doped with Fe. This ash couldbe a suitable choice upon which to base an Fe-doped cordierite material.By starting with Elk Creek bituminous ash from Table 1, then addingapproximately 8 wt % Al2O3 and 8 wt % MgO, a renormalized composition of51% SiO2, 34% Al2O3, 8% MgO and 7% Fe2O3 may result, which is close to acomposition of Fe-doped cordierite Similarly, Wyodak PRB coal ash may bea useful material from which to form Gehlenite (2CaO—Al2O3-SiO2), andseveral ash compositions are close to mullite-cordierite compositions ofbodies having advantageous properties (shown as compositions B, C, and Ein Table 1).

Certain embodiments include a database of ash properties, formingprocesses, and methods to calculate body vectors based thereon. An ashsource may be matched to a desired application based on a probability orother figure of merit describing the likelihood that the ash source canbe developed into a body for that application.

Certain aspects include matching a source of particles to a desiredapplication. For example, a first direct-injection engine may use lowpressure injections of larger fuel volumes, and create large amounts ofsoot particles in the “PM10” regime (i.e., approximately 10 microns),which may require a certain size porosity for its removal, which may becreated using a first particle size distribution and/or first fugitivephase. A second direct-injection engine may use higher injectionpressures, multiple small injections, and even a lower molecular weightfuel (e.g., gasoline). This second engine may create smaller particles,many of which may be below 2.5 microns (e.g., PM2.5), and their removalmay require a body having finer porosity than for the first engine. Asecond particle size distribution, size cut, fugitive phase, formingmethod or other factor may be used to create this finer porosity.Various embodiments include systems and methods for high throughputexperiments directed toward synthesizing a plurality of samplescontaining different source materials and screening them for propertiesassociated with an application, often based upon a vector ofrequirements associated with that application.

Various methods may be used to calculate and/or estimate the propertiesof a body, including experimental measurements. Optimization methods(e.g., least squares, monte carlo, steepest descent, parallel tempering)may be used to find a body vector that matches an application vector.For a given ash source, data such as composition, particle sizedistribution, particle shape, LOI, and crystal structure (or assemblagethereof) may be combined with thermal data (differential thermalanalysis, dilatometry (DTA), thermogravimetric analysis (TGA),differential scanning calorimetry (DSC)) to predict the behavior of theash during and subsequent to a forming operation. Some embodimentscreate parameter vectors describing materials source properties andforming data to estimate body vectors for hypothetical bodies. Thesedata may be combined with models describing fluid flow and fluidinteractions with the body to predict the properties of a body based ona particular ash source (optionally subject to a particular formingprocess such as molding, firing, burnout, etc.). These body vectors maybe matched to one or more application vectors to evaluate fit, and insome cases, adjustable parameters in the body vector inputs areiteratively optimized in order to better match a body vector to anapplication vector. The application vector may also be iterativelymodified with the body vector in a calculation that best matches an ashsource, a processing method, a set of geometrical and other constraintsand other factors to a set of application constraints.

Exemplary ash sources, particle sizes, phases, compositions, and otherash properties are disclosed herein for illustrative purposes.Similarly, properties of various bodies such as shape, size, thermalcharacteristics, permeability, porosity, density and the like are forillustrative purposes. Applications such as liquid metal filtration,exhaust gas mitigation, flue gas purification, water treatment, dieselor direct-injection particulate removal, the catalytic removal ofspecies (e.g., NOx, hydrocarbons, CO and other species), mercuryremoval, sulfur removal and the like are for illustrative purposes.

Select aspects include computing devices, networking components,databases, storage, servers and the like, generally including at least aprocessor, memory, storage media, input, output, display, communicationscircuitry, and a database comprising ash data, materials properties,matching methods, forming data, and application data. Certainembodiments include a computer-readable storage medium having embodiedthereon a program operable by a processor to perform a method. Certainmethods include selecting an application for which a body is needed anddetermining an ash source and optionally processing parameters thatshould yield the desired body. Bodies may be fabricated, measured, andthe measured properties may be compared with predicted properties.

Many industrial-scale combustion processes (e.g., electricitygeneration, industrial heating, coal combustion, municipal solid wasteincineration and the like) are regulated by governments, and so lists ofash sources are readily available. For example, the state ofPennsylvania in the United States currently includes over twenty coalfired power plants, ranging from the New Castle and Bruce Mansfieldplants in the western part of the state, to the Portland, Martins Creekand Eddystroke plants in the eastern part of the state. The UnitedStates obtains over 50% of its energy from coal, and many othercountries produce significant quantities of coal fly ash, wasteincineration ash, or both. As such, there is a large supply of ash inmany countries, the magnitude of which provides for both a wide range ofash compositions and a substantial amount of each particularcomposition. Ash products may be available with particle sizes rangingfrom below 1 micron to above 1 mm For some bodies, preferable ashparticle size distributions may range from 0.1 microns to 100 microns,with average particle sizes in the range of 5-50 microns. In someembodiments, one or more ash sources having broad particle sizedistributions is identified, the ash source is sieved to createsequential “cuts” of various particle size ranges, and one or more cutsis selected. Different cuts from the same and/or different materialssources may be combined.

FIG. 1 is a diagrammatic representation of an exemplary embodiment. Afluid 100 substantially penetrates a porous body 110 comprised of ashparticles 120. Generally, interactions between a fluid and body mayinclude a container or package, containing the body, having inlet(s) andoutlet(s), and configured to confine the fluid to a desired flow path.For clarity, such containers are generally omitted from figures. Ashparticles may have a relatively narrow particle size distribution, awide particle size distribution, a bimodal or multimodal particle sizedistribution or other distribution as desired. Ash particles may besubstantially monodisperse. Particles may be connected, bonded orseparate. Ash particles may come from one or more different ash sources,and in some aspects, a first size distribution is selected from a firstsource, and a second size distribution is selected from a second source,and the distributions are combined.

Particles may be bound to each other via interparticle bonds 130.Interparticle bonds 130 may include necks or other connectivestructures, or forces between particles (e.g., Van der Waals forces).Formation of interparticle bonds 130 may include the use of cementitiousbonding, aqueous chemical bonding, or other relatively low temperaturereactions between and/or with particles. Formation of interparticlebonds 130 may include diffusion, sintering or other higher reactionsbetween and/or with particles. In some applications, some particles arebonded and some are not. In certain aspects, control of interparticlebonding may be used to control compliance, thermal shock resistance,thermal shock damage resistance, and other factors. Certain aspectsinclude the addition of components that aid the formation of desiredinterparticle bonds 130, and in some cases, these components aredifferent than the material of ash particles 120. In a preferredembodiment, a first ash source provides a desired permeability, and asecond ash source enhances bonding. In another embodiment, a first ashsource provides a desired permeability, and a second ash source enhancesviscoelastic properties of a paste used to form the body.

Porosity may be characterized by factors including pore sizedistribution, pore connectivity, and/or pore shape. Pore connectivityand/or pore shape may be isotropic or anisotropic. In some aspects, apore connectivity may be designed that optimizes both fluid interactionand mechanical properties. Some porosity may be anisotropic with respectto (e.g.,) various body dimensions. A pore size distribution may take avariety of forms, including Gaussian, normal, lognormal, multimodal,bimodal, trimodal, skewed, Weibull, or any other desired distribution.Porosity may also be characterized by macroscopic factors (e.g., %porosity, surface area, permeability and the like). Various applicationsmay require different combinations of mean pore diameter and percentageopen porosity.

FIG. 2 is a diagrammatic representation of an exemplary embodiment. FIG.2 shows an application in which flowing fluid 200 interacts with porousbody 210. An exemplary application may be one in which body 210catalyzes a reaction in fluid 200. Generally, such an application mayinclude a transition region 220, over which fluid transport may changefrom laminar or turbulent flow near the surface to substantiallydiffusive transport within the body. Various embodiments may includemeans to move the fluid, including pumps, fans, gravity, a pressurehead, electrochemical gradients and the like. Fluid passage past thebody may also be characterized by a shear force 230 at the fluid/bodyinterface. Even when fluid 200 has a significant linear velocity pastbody 210, porosity of body 210 may create a broad range of local flowrates within transition region 220, generally decreasing with depth intothe body. As such, a wide range of residence times, diffusive reactionsand catalytic processes may be created, depending upon a depth withinthe body.

A reaction may include a reaction between more than one fluid and a body(e.g., a reaction involving a gas phase and a liquid phase). Variousembodiments include an electrochemical or similar type of reaction(which may include ions, electrons or other species).

In some aspects, it may be advantageous to choose a pore sizedistribution that optimizes (e.g., maximizes subject to mechanicalrequirements) the surface area of the body exposed to fluid 200, and itmay also be advantageous to form channels in the body thatmacroscopically expose a significant fraction of the body to the fluid.In certain aspects, channels may be formed by a material (e.g., a firstash source) providing structural properties, and a second materialwithin the body (e.g., a second ash source) provides fluid treatmentproperties (e.g. a desired reactivity). In some aspects, bodies arecomposites of two, three, four, five, six, or more phases. In someembodiments, a body comprises two phases, each of which may include ashparticles. A first phase may include first particles below 200 mesh anda second phase may include second particles below 0.2 microns. Thesecond phase may have surface area greater than 20 m̂2/g, and preferablygreater than 100 m̂2/g, and exemplary particles include transition-metalor rare earth (e.g., Mo, Ce, La, Zr) sulfides and/or oxides, and mayinclude zeolites. In a preferred application, the first phase comprises50-90% by mass, and the second phase comprises 10-50% by mass.

FIG. 3 is a diagrammatic representation of an exemplary embodiment. FIG.3 shows an application in which fluid 300 is passed through a body 310(e.g., in filtration or sparging). Often, such applications include theremoval of a species by using a porosity that allows passage of fluid300 but substantially blocks the passage of a species entrained withinfluid 300. Typically, body 310 may be characterized by one or morelengths 320. Length 320 may describe a minimum length that must betraversed by the fluid in passing through the body. The passage of fluid300 through body 310 may be caused by a force 330. In some applications,force 330 includes a component substantially parallel to length 320, andfor relatively small lengths 320 (based on the pressure associated withforce 330 and the mechanical properties of body 310), body 310 should bestrong enough to maintain mechanical integrity during use. Suchapplications may require packaging, containment, interparticle bondingor other aspects such that the body mechanically resists the pressurecreated by force 330 while allowing the passage of the fluid 300. Incertain applications, length 320 is approximately 50-1000 microns. Inother applications, length 320 is approximately 1-5 mm. In still otherapplications, length 320 is approximately 1 cm, and in furtherapplications, length 320 is greater than 10 cm, and in some applicationslength 320 is greater than 0.1 m. In certain embodiments, length 320 isapproximately 800 microns and body 310 has a median pore size between 5and 50 microns.

Various applications may require different combinations of mean porediameter, percentage open porosity, and length 320. Factors such as asize of a species being removed, the concentration of that species influid 300, a desired flow rate of fluid 300 through body 310, a strengthof body 310, particularly with respect to force 330, the tendency of areacted species to affect (e.g., clog) body 310, and other factors maybe used to determine the desired properties of body 310. In someembodiments, body 310 includes a length 320 between 100 and 900 microns,fluid 300 is a gas, body 310 is removing substantially solidparticulates associated with direct injection combustion. In someembodiments, a relationship between a percentage of open porosity (OP %)and a mean pore diameter (MPD, in microns) is given by: OP%=75-1.46*MPD. In some cases, OP % may vary by up to 30% above and/orbelow this relationship (i.e., the relationship may be a “band”). Incertain embodiments, porosity may be between 30-70%, and MPD may bebetween 5 and 60 microns.

FIG. 4 provides a diagrammatic representation of a representativesection of a channel embodiment. Channels, tubes, planar passages andthe like may provide for substantially unimpeded fluid flow within,while increasing exposure of the fluid to channel walls. In thisexample, a channel is blocked, forcing passage through the body materialper se (e.g., through a wall to an adjacent channel). In otherembodiments, channels are not blocked, and fluids flow freely throughthe body via the channels. In FIG. 4, fluid stream 400 flows into body410 in a first direction, generally parallel to one or more channels 405incorporated into body 410. Alternating channels 405 and 407 may becreated to maximize the region of body 410 through which fluid stream400 can pass, shown as regions having length 420. Fluid stream 400 maypass through a first channel 405 into an adjacent channel 407 via a wall(of length 420) between the channels. Body 410 may include porosityhaving a pore size distribution that allows passage of fluid stream 400while blocking a substance 440 entrained in gas stream 400. In certainaspects, substance 440 may be blocked substantially “within” body 410(e.g., within the walls). In other aspects, substance 440 may be blockedsubstantially at the interface between body 410 and channel 405. Incertain cases, substance 440 may form a layer that affects thepermeability of body 410. In some aspects, the cross sectional area ofeach channel (i.e., the area of a channel facing the fluid flow) is thesame. In other aspects, different channels have different crosssectional areas. In embodiments in which a substantial amount ofsubstance 440 is expected to deposit on or in channel 405, channel 405may be made larger than adjacent channels (e.g., channel 407) such thatthe effective flow rates of the two channels are better matched aschannel 405 “fills up” with a blocked substance 440. Channels may have across section that is circular, square, hexagonal, octagonal, triagonal,and/or other shapes.

Various geometric designs may be used to maximize area exposed to thefluid while increasing the “wall strength” associated with channels in abody. Many of these designs combine thin walls (e.g., small lengths 420)with regularly spaced supports that reinforce channels against pressureexerted by fluid stream 400.

FIG. 5 is a diagrammatic representation showing an alternating channeldesign according to certain aspects. Body 510 may be a porous bodycomprised of ash particles, and may generally be contained in acontainer (not shown). In this example, body 510 includes alternatelyblocked parallel channels 505 and 507, in which channels 505 are blockedat a first side of the body, and channels 507 are blocked at a secondside. Alternating channels may be blocked at opposite ends with plugs520. Generally, channels 507 may be blocked at a first end of body 510,so a fluid passes into body 510 via channels 505. Similarly, channels505 may be blocked at a second end, such that a fluid exits body 510 viachannels 507. As such, a fluid passing through body 510 may be forcedthrough the solid regions of the body (e.g., the walls separatingchannels 505 from channels 507. Characteristics (e.g., cross sectionalarea, length, channel dimensions, number of channels, wall thickness,permeability, operational temperature capability, thermal properties,mechanical properties, chemical properties and the like) required of abody such as body 510 are generally defined by a particular application.For example, a diesel particulate filter may include a material capableof sustained operation at over 400 degrees, cycling to over 1000degrees, having a porosity between 30 and 60%, having a median pore sizebetween 2 and 30 microns, have a permeability of at least 0.5E-12/m̂2(preferably greater than 1E-12/m̂2), modulus of rupture greater than 10Mpa (preferably above 100 MPa), and a thermal expansion coefficient lessthan 1E-5/degree Celsius.

For applications not requiring flow through walls (e.g., a catalyticconverter), plugging the ends may be unnecessary, and the channelgeometry of body 510 (absent the end plugs 520) may be used to maximizea surface area available for reaction. In some aspects, it may beadvantageous to incorporate porosity such that a body has a surface areagreater than 1 m̂2/g, 10 m̂2/g, greater than 40 m̂2/g, or even greater than100 m̂2/g.

Bodies may be fabricated from ash sources containing or yielding one ormore desired phases, depending upon an application. Desired phases mayinclude cordierite (2MgO-2Al2O3-5SiO2), mullite (3Al2O3-2SiO2),β-spodumene (Li2O—Al2O3)2-8SiO2, Aluminum Titanate (Al2TiO5), AluminumTitanate-Mullite, magnetite, maghemite, spinels, garnets, wollastonites,perovskites, and other mixtures thereof. Various bodies may includeAluminum Titanate doped with Fe2O3 and/or rare earth oxides (La2O3,Nd2O3). Additional components (sintering aids, catalysts, and the like)may be added to a mixture comprising ash particles in order to modifycomposition as desired.

Although a body such as body 510 may be fabricated from a variety ofmethods, it may be advantageous to extrude body 510. In such cases, itmay be advantageous to extrude a paste having non-Newtonian viscoelasticcharacteristics, and in some cases, it may be advantageous to use ashear-thinning paste. A variety of methods exist to adjust therheological properties of pastes, slurries and the like, and thesemethods generally apply to pastes, slurries, and the like thatincorporate ash particles. Admixtures (e.g., as used in cement rheology)may be added between 0.01 and 10%. Lignosulfonates and/or otherlignin-containing compounds may be used, generally between 0.01 and 5%.Exemplary sources of lignosulfonates include spent sulfite liquors fromcellulose processing plants. Various organic materials may also be usedto modify rheology, including methylcellulose, polyvinyl alcohol (PVA),polyethylene glycol (PEG), vinyl acetate and vinyl pyrrolidone.Exemplary recipes include an ash source, a liquid carrier (e.g., water)of approximately 10-50% by weight of the ash source, a cellulose bindersuch as methylcellulose in the range of 1-20% by weight, and optionallya detergent and/or surfactant in the range of 0-3% by weight. Someembodiments include the addition of ethylene glycol, fatty acids,polyvinyl alcohol, and/or other organic species, generally in the rangeof 0-10 wt %.

In certain embodiments, a fugitive phase is used, often in the range of10-80% by weight, in order to enhance porosity. A fugitive phase may bepresent in an as-received ash source, such as a fly ash havingsubstantial residual carbonaceous species. A fugitive phase may also beadded separately. Various substances added to modify forming processes(e.g., methylcellulose) may also be fugitive phases. Exemplary fugitivephases include graphite, potato starch, polyethylene particles,polyvinyl acetate particles, or other materials capable of influencingthe final microstructure before being removed from the body.

In certain aspects, composition may be modified through the addition ofone or more components designed to react with the ash. Such componentscould include, without limitation, MgO, SiO2, colloidal SiO2, TiO2, FeO,Talc, kaolin, boehmite, various Al2O3 species (e.g., γ-Al2O3, α-Al2O3),gypsum, phosphorous-containing compounds, SiC, Al, Co, Fe, Ni, Ba, Pb,lanthanides, sulfides, zeolites, rare earth compounds and the like.

Rheological properties may be enhanced by using a multimodal particlesize distribution. In certain cases, a mixture of between 30-90% of alarge particle size cut (e.g., particles greater than 10, 20, 30, 40, 50or more microns) may be combined with a complementary amount of a smallparticle size cut (e.g., below 10, 5, 3, 1, or 0.1 microns). In certainembodiments, a bimodal particle size distribution is used, with firstand second distributions mixed in approximately equal amounts, and thesecond distribution having a mean particle size that is ˜5-25% of themean particle size of the first.

For extruded bodies requiring further processing (e.g., channelplugging), it may be advantageous to inject a thick paste (typically ofsimilar composition) into channels requiring it. For bodies fabricatedby assembling one or more substantially planar pieces, doctor blading orother methods to synthesize planar bodies may be used, and planar piecesmay be bonded together with a paste or slip.

In some embodiments, walls associated with channels may be substantiallyplanar. In other embodiments, walls may be curved.

Forming a body may include forming cementitious or other hydrated bondsamong particles. Some ash compositions may be capable of formingcementitious bonds without additional components. In certain cases,complementary components (e.g., CaO, MgO, or other components) are addedto an ash composition such that the combined composition formssubstantially cementitious bonds. Some bodies may include pozzolanicmaterials, and some of these may include the addition of complementarymaterials to enable the formation of desired phases.

Some bodies may be fired. Firing may be used to remove a fugitive phase(e.g., via combustion of a carbonaceous fugitive phase). Firing may alsobe used to aid the formation of interparticle bonds (e.g., necks).Firing may also be used to change the composition, crystal structure,particle size, grain size, and other aspects of a body. Selectembodiments include selecting a first phase for forming a body, reactingthe first phase to form a second phase during a forming operation, andin some cases, forming a third phase during a firing operation.

Firing times and temperature may generally depend upon a desiredapplication and body properties directed thereto. Generally,applications requiring more refractory bodies may require equivalentlyhigher firing temperatures. In some aspects, bodies are fired attemperatures between 400 and 800 Celsius. Bodies may be fired attemperatures between 800 and 1200 degrees Celsius. Some bodies may befired at temperatures between 1200 and 1800 degrees. Some bodiesincluding cordierite may be fired at temperatures between 1000 and 1600degrees. Some bodies including mullite may be fired at temperaturesbetween 1000 and 1950 degrees. Bodies requiring low temperature firingmay be enhanced by using ashes containing network modifiers such as K2Oand Na2O, or by adding these components. Bodies for use at temperaturesabove 500 Celsius may perform better by choosing an ash source havinglow (preferably negligible) amounts of less refractory materials such asK2O and Na2O. Certain compositions may form a liquid phase that firstenhances bonding, then reacts to form a solid phase (e.g., as inreactive sintering).

Certain aspects include firing in a coal fired, gas fired, microwaveenhanced, and/or electric furnace. In some cases, firing includescontrolled atmospheres, which may include oxidizing, reducing, forminggas, Nitrogen, and other atmospheres. Firing may be done in air. Somebodies do not require firing. Firing atmospheres may include theaddition of a gaseous component to prevent an undesired evolution of asubstance during firing (e.g., an overpressure of a gas).

Body 510 may be appropriate for filtration. By choosing a substantiallyinorganic ash material, particularly a composition tending to form arefractory phase such as cordierite, spinel, mullite, indialite,corundum, aluminum titanate, and/or combinations thereof, body 510 maybe made refractory, and so may be useful for the filtration of hotfluids such as molten metals or hot gases. In select embodiments, atemperature of operation includes a range between 200 and 1200 degreesCelsius. In some embodiments, a body is formed having a first pore sizedistribution, the body is treated with a fluid containing particles thatare substantially filtered by the body, the fluid is removed (leavingthe particles), and the body and particles are processed (e.g., fired)to create a body having a second pore size distribution. An exemplaryfluid may be air, and exemplary particles may be fine particles yieldinga composition similar to (or complementary to) a composition of thebody. In certain cases, the body and/or particles comprise ashparticles. Some bodies include celsian phases.

In some aspects, a body may include 60-95% porosity, have an airpermeability between 100 and 10,000E-7 cm̂2, have between 5-70 pores perinch, and be between 0.1 and 10 inches thick.

Body 510 may be used for the filtration of particulates associated withcombustion, and in some cases, body 510 may be used in an applicationinvolving diesel engine combustion. In exemplary applications, body 510may have between 4 and 500 channels per square inch of area (orthogonalto the channels). In other embodiments, body 510 may have fewer than 5channels per square inch, and in some cases, fewer than 0.1 channels persquare inch. In certain embodiments, body 510 has more than 600, 800, oreven 1000 channels per square inch. Some versions of body 510 may removeparticulate matter from a diesel exhaust stream, including particulatematter characterized as PM10 and/or PM2.5 and/or other matter. In someexamples, particulate matter may be reduced to a level below 1, 0.5,0.1, 0.05, or even 0.01 g/bhp-hr, as normalized to an engine of aparticular brake horsepower generating the particulate matter beingremoved by the body from the associated exhaust gas stream. Certainembodiments include a body for removing at least some pollutants in anengine exhaust stream to a level below that of USEPA Tier 2 Bin 10, US2007 HD, and/or Euro V, and preferably USEPA Tier 2 Bin 5 (or even Bin2), US2010 HD, and/or Euro VI.

In some embodiments, body 510 may have a wall thickness between about 50microns and 2 mm, may have porosity between 10 and 90%, preferablybetween 20 and 80%, may have a mean pore size between 1 and 60 microns.In some aspects, body 510 may have a median pore size between 4 and 22microns. In certain embodiments body 510 is characterized by apermeability of at least 0.2E-12/m̂2, and preferably at least 0.8E-12/m̂2.In certain embodiments, body 510 may have a heat capacity greater than 3Joules/(cm̂3-K). In some cases, fine ash particles (e.g., below 325 mesh)may be agglomerated or pelletized into partially dense pellets, a bodyis then fabricated from the pellets, and body porosity at leastpartially results from porosity of the agglomerates.

In certain aspects, body 510 has sufficient permeability and dimensions(e.g., wall thickness, channel surface area, cross section) to allow agaseous fluid to pass through body 510 at a linear velocity greater than0.01 ft/second, preferably more than 0.1 ft/second, preferably greaterthan 0.5 ft/second, more preferably above 3 ft/second, and still morepreferably above 10 ft/second.

Body 510 may be disposable, and be of a large enough size that arequired treatment lifetime is achieved. Various lifetimes may beappropriate, including a replacement cycle in an automobile, train, shipor truck, a usable life for an offroad diesel apparatus, the length of ajourney associated with a railway engine or ship, a duty cycleassociated with a harbor vessel or associatedloading/unloading/transport equipment, a harvest season associated withfarm equipment, an oil change interval associated with an engine, andother lifetimes. Lifetime may include a certain number of “start-stop”operations associated with testing of a piece of backup equipment toverify performance. Some bodies may have a volume below 0.1 m̂3. Otherbodies may be between 0.1 and 1 m̂3. Certain bodies may be between 1 and10 m̂3, and some bodies may be greater than 10, or even greater than 100m̂3 in volume. Some bodies are approximately the size of a shippingcontainer.

In certain applications, body 510 may be regenerated during use, and insome cases, regeneration includes the combustion of particles filteredfrom a fluid stream passing through body 510. Regeneration may includeoxidizing environments, and may involve temperatures above 400, 500,600, 700, 800, 900, 1000, or even 1100 degrees. In some aspects, aregeneration temperature includes a range between 600 and 1100 degrees.For such applications, body 510 may fabricated from ash particlesyielding compositions and crystal structures appropriate for thetemperatures and chemical nature of a fluid to which body 510 isexposed. In some applications that include regeneration, body 510 may befurther comprised of materials that can withstand a temperatures andenvironment associated with regeneration, including any speciesintroduced in the context of an active regeneration cycle and/orthermoelastic stresses associated with regeneration. Regeneration mayinclude backflushing.

Certain aspects include the use of processors that provide for thecalculation of a lifetime or duty cycle associated with a treatmentprocess, and in certain cases, the duty cycle may include a time until aregeneration process occurs. In certain embodiments, data are gatheredand stored (e.g., in RAM or on storage media), and a time until an endof a duty cycle is calculated, often repeatedly. In some cases,operation or use of a body in an application includes calculating anexpected time until an end of a duty cycle, and in some cases, adjustingoperation accordingly. In certain cases, a duty cycle includes anestimated trip time, route distance, operation time, or other timeand/or load-dependent characteristic, and in certain aspects, thisestimated time is used to adjust a process involving the body. Incertain cases, a predicted route (e.g. a garbage delivery route or acalculated route from “route mapping” software) is used to estimate aset of operation conditions. For example, a decision to operate the bodyin a first way (e.g., regenerate a diesel particulate filter) or asecond way (not regenerate) may incorporate the predicted route or dutycycle. In select embodiments, a predicted time or distance traveled isused to determine a process adjustment that may include a regenerationstep. A predicted duty cycle may be used to predict a time at which abody is expected to reach a use temperature, and in certain cases, tocontrol a starting point of a regeneration process according to theprediction. In some cases, a regeneration process may be delayed becausean estimated duty cycle time is too short to provide for completeregeneration. In other cases, regeneration may be started “early” (e.g.,via additional heating of the body) in order to complete regenerationbefore the end of the duty cycle. Engine data may be used in any ofthese calculations, and certain aspects may include the control ofengine control parameters (e.g., injection timing, post-injection,amount of exhaust gas recirculation).

FIG. 6 is a diagrammatic representation of an exemplary embodiment. FIG.6 shows an apparatus 600 in which a porous body comprised of discreteparticles is substantially contained by a package. In variousembodiments, the discrete particles include ash particles, and the bodymay comprise more than 10%, 30%, 70% or even 90% ash particles. Body 610includes ash particles having a particle size distribution such thatfluid 602 may pass through body 610 from an input 620 to an output 640(or in the opposite direction). Typically, body 610 is contained by apackage 650 that includes a layer having both sufficient strength tocontain body 610 and sufficient permeability to permit passage of fluid602. In some aspects, fluid 602 flows through body 610 via gravitationalforces. In other aspects, fluid 602 may be driven through body 610 viaan applied pressure.

Body 610 may include a single type or several types of particles. Incertain cases, body 610 may be stratified, such that layers of differentparticles are disposed at different points (with respect to a directionof fluid flow). In certain cases, layers are stratified from input 620to output 640 from coarse to fine. Exemplary coarse particles may begreater than 100 micron, 500 micron, 1 mm or even 1 cm, and exemplaryfine particles may be less than 100 micron, less than 50 micron, lessthan 10 micron, less than 1 micron, or even less than 100 nm. Certainaspects provide for several (two, three, five or even ten) discreteparticle size distributions, and in some cases layers comprising eachdistribution may be ordered from large to small. Certain embodiments mayuse ash particles ranging from 0.2 to 5 mm in size.

Particles having different densities may be distributed at differentvertical points, particularly in cases with substantially vertical flowas in FIG. 6. Thus particles closer to the “top” may have lowerdensities, and particles closer to the “bottom” may have higherdensities. In many aspects, backflushing may be used to clean body 610,and the resistance of body 610 to disruption due to backflushing may beincreased by using less dense particles near the top/input and denserparticles near the bottom/output Similarly, a filtration efficiency maybe improved by siting coarser particles near input 620 and finerparticles near output 640. Different ash sources having differentchemical compositions may be used to choose appropriate particlesources. Additionally, many ash sources have broad ranges of particles,and so an arbitrary cut of a subset of particles may be chosen from anas-received particle size distribution. In a preferred embodiment, body610 is stratified, with a first layer comprising larger, less denseparticles near the top, and at least one second layer comprising denser,smaller particles near the bottom.

In some embodiments, an apparatus as shown in FIG. 6 may be operated asa fluidized bed (e.g., by driving a fluid 602 “upward” through aperforated/permeable bottom 660 that supports body 610 but allowspassage of fluid 602). In certain embodiments, the properties of body610 (and/or the treatment of fluid 602) may be improved by applyingsuitable mechanical (e.g., vibration), electromagnetic, acoustic orother forces.

FIG. 7 provides a diagrammatic representation of an exemplaryembodiment. FIG. 7 shows an apparatus 700 capable of interaction with afluid 702. Apparatus 700 includes a porous body 710 comprised ofsubstantially loose particles contained by a package. In variousembodiments, the loose particles include ash particles, and the body maycomprise more than 10%, 30%, 70% or even 90% ash particles. In thisexample, body 710 includes ash particles substantially contained bypackage 750, which includes a plurality of angled pieces 752. The design(e.g., angle, length) of angle pieces 752 is chosen in concert withvarious properties of ash particles included in body 710 (e.g., particlesize distribution, density, interparticle attraction) such that in someaspects, substantially “loose” ash particles may be disposed in asubstantially vertical package 750, held in place at an “angle ofrepose” associated with the settling of the ash particles against theangled pieces 752. In such an example, a fluid 702 may be introducedhorizontally as shown, and caused to pass through body 710. In certainaspects, ash particles are continually fed into package 750 during use.Particles may be continually replenished (e.g., at the top of body 710)during use, and in some cases, the permeability of a body (e.g., body710) may be dynamically modified by changing the particle sizedistribution associated with body 710 during use.

Body 710 may act as a cross flow gas contactor. In certain aspects, theproperties of body 710 may be improved via the application ofelectrostatic and/or electromagnetic forces, and in some cases,properties may be improved by incorporating magnetic particles into body710. Magnetic particles may include magnetic ash particles, such as ashparticles comprising magnetite (Fe3O4), maghemite (Fe2O3) and the like.Magnetic Fe, Ni, Co, and mixtures thereof may also be included in body710. The use of particles having a Curie temperature above a temperatureof a fluid 702 being treated may be advantageous.

Apparatus 700 may be used to treat an exhaust stream from a combustionprocess, and in some cases electric power (possibly from the combustionprocess) is used to create an electromagnetic field associated with body710. In certain versions, “normal” operation includes filtration of anexhaust stream, and normal filtration is enabled by an electromagneticfield acting on body 710. “Abnormal” operation may be used to providefailsafe operation, (e.g., to provide for reduced filtration inemergencies), and may be controlled via control of the electromagneticfield. In certain embodiments, abnormal operation results in fluid 702substantially bypassing body 710. In other embodiments, abnormaloperation results in fluid 702 “breaking through” the permeable barriercreated by body 710.

FIG. 8 is a flowchart of a process according to certain embodiments.Such a process may be performed by a processor executing a method 800.In step 810 an application vector is determined. An application vectormay describe various characteristics of an application in which a fluidand a body interact. An application vector may also include a desired ortargeted body vector, associated with a body appropriate for theapplication. In step 820, one or more source materials is selected.Selection may include querying a database of source materials, which maycomprise ash sources, non-ash sources, particle sizes available, LOI,XRD data, chemical composition and the like. For some materials, asubset of particles from a materials source may be selected, which mayinclude sieving, filtration, floatation, magnetic separation, densityseparation and the like. For some materials sources, “subset” mayinclude the entirety of the materials source. Optional step 830 may alsobe performed, in which case a forming process (including formingparameters) may be defined. Forming processes include casting,vibrocasting, injection molding, extruding, and other operations.Forming processes may include recipes for pastes or clays, burnoutschedules, firing cycles, heat treatments, ambient atmosphere and otherprocesses. A body vector is calculated in step 840, which may includeselecting a first composition and a first forming condition andcalculating properties of a body formed accordingly. In step 850 thebody vector is compared to the application vector, and in step 860 aquality of match between the body vector and application vector isdetermined (e.g., how well the body is expected to work for theapplication). Depending upon fit quality, an iterative loop betweensteps 820/830 and step 860 may be performed. Typically, one or moreinput parameters (e.g., composition, particle cut, ash source, bindervolume, extrusion pressure, firing cycle, dwell time and the like) maybe modified for each iteration, and the result of the iteration on matchquality is recorded. As such, a multidimensional parameter space may besampled, wherein each point in the space corresponds to a differentvalue of one or more parameters (e.g., in a body vector or applicationvector). In some cases, input parameters are adjusted until asatisfactory match is obtained. Steps 810, 830, 840, 850, and 860 may becomplemented by experimental data, and experimental results may besubstituted for calculated results. Some aspects include networkedcommunications, and may include communications with automatedexperimental equipment. In certain embodiments, a multidimensionalparameter space, comprising chemical, physical, structural, phase andother parameters, may be sampled, and sampled points may be evaluatedfor applicability to an application.

Several illustrative examples are described as follows for illustrativepurposes, and are not intended to limit the scope of the claims.

FIG. 9 shows particle size and composition information for an exemplaryash source. Described herein as Boral 35, this source was provided byBoral Material Technologies, San Antonio, Tex. Laser light scattering(Horiba LA910, Horiba Laboratory, Irvine, Calif.) showed a range ofparticle sizes in this sample, from below 1 micron to above 500 microns,with an average particle size of approximately 35 microns, and thefollowing statistics: D10=3.3 microns; D50=22 microns; D90=98 microns.DTA/TGA analysis of this material in air at 10°/minute (LinseisL81/1550, Linseis, Inc., Robbinsville, N.J.) showed less than 1% weightloss, with no apparent melting, up to 1250 C. Many particles in thissource are spherical or spheroidal, which in some embodiments may beused to improve paste properties (e.g., extrudability) and/or the easewith which materials comprising these particles may be modeled. Thechemical composition (qualitative SEM/EDS, Jeol JSM 5610/EDAX detector)showed oxides of Si and Al, with smaller amounts of Fe, Mg, Ca, K, Na,and Ti.

FIG. 10 shows particle size and composition information for anotherexemplary ash source. Described herein as Boral 3, this source wasprovided by Boral Material Technologies, Rockdale Tex., and purportedlyresulted from the Sandow Power Plant (Texas). Laser light scatteringshowed a distribution of particle sizes from ˜800 nm to 10 microns, withan average particle size of approximately 3 microns, and generallyspherical particles, and the following statistics: D10=1.6 microns;D50=2.8 microns; D90=4.6 microns. DTA/TGA analysis of this materialshowed less than 1% weight loss, with no apparent melting, up to 1250 C.

FIG. 11 shows particles size information for an additional exemplary ashsource. This material (ProAsh, Separation Technologies/Titan America,Troutville, Virgina). This source purportedly came from the BrunnerIsland Power Plant (Pennsylvania), and had a reported major compositionof approximately 54% SiO2, 28% Al2O3, 9% Fe2O3. This material had aparticle size distribution as shown, with D10=4.5 microns, D50=45microns, and D90=341 microns, and reported LOI=1.5%. DTA/TGA analysis ofthis material showed approximately 1.8% weight loss, with no apparentmelting, up to 1250 C.

FIG. 12 shows particles size information for an additional exemplary ashsource. This material (Ecotherm, Separation Technologies/Titan America,Troutville, Virgina), is described herein as Pro-Ash Hi Carbon. Thissource was purportedly a bituminous coal fly ash from the Brunner IslandPower Plant (Pennsylvania), and was reported to include a substantialamount of residual carbonaceous species. This material is an example ofan ash source providing an “intrinsic” fugitive phase. This material hada particle size distribution as shown, with D10=9.6 microns, D50=36microns, and D90=105 microns. DTA/TGA analsyis showed weight lossbeginning at approximately 500° C. and continuing for several hundreddegrees, and the sample lost approximately 40% of its mass. This samplealso showed a phase transition (possibly melting) at 1130° C.

Extrinsic fugitive phases included two graphite sources from AsburyGraphite Mills (Asbury, N.J.): a fine particle size (A99) graphite,having D10=6.1 microns, D50=23 microns, D90=51 microns, and a coarseparticle size (4012) graphite, having the following particle sizestatistics: 0.22% above 180 microns, 0.9% above 150 microns, 72% above75 microns, 24% above 44 microns, and 2.8% below 44 microns.

Several different mixtures (i.e., clays or pastes) were made forfabrication into bodies. Table 2 lists recipes associated with theserecipes, and also includes methods used to shape these pastes intoforms. Several samples were formed using extrusion, and includedrheology modifiers (YB-155 and YB-113C, Yuken America, Novi, Mich.)which may also function as fugitive phases. Other samples were formed bycasting samples into a ceramic crucible, tapping the crucibleapproximately 20 times to settle the sample and allowing the sample toset (described herein as vibrocasting).

TABLE 2 Batch Compositions - 100 wt. % of total solids (ceramic andgraphite raw materials) and Liquid Sample: 1 2 3 Baseline 2F 3F 4F 6C 7C8C 8C-5 MATERIALS Boral 3 μm 31.3 31.3 44.8 31.5 29.8 26.7 19.6 29.325.6 17.7 17.7 Boral 35 μm 31.3 31.3 — 42.2 39.9 35.8 26.3 39.2 34.223.7 23.7 Pro-Ash High — — 24 — — — — — — — — Carbon Ashbury A99 — — — —3.2 8.7 21.4 — — — — Graphite^(a) Ashbury 4012 — — — — — — — 4.9 12.729.3 29.3 Graphite^(b) Darvan C — — 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2Yuken YB155 8.3 8.3 — — — — — — — — — binder/plasticizer Yuken YB133C8.3 8.3 — — — — — — — — — binder/plasticizer DI Water 20.9 20.9 31 26.126.9 28.6 32.5 26.4 27.3 29.1 29.1 FORMING Method Extruded ExtrudedExtruded Vibrocast Vibrocast Vibrocast Vibrocast Vibrocast VibrocastVibrocast Vibrocast Shape Tube Solid Rod Solid Rod Disk Disk Disk DiskDisk Disk Disk Disk FIRING Cycle # 1 1 1 1 2 2 2 2 2 2 3 POROSITY Med.Pore Dia. 2.0 2.1 3.7 1.8 2.3 3.2 6.4 2.2 3.2 11.8 12.2 (microns)^(c)Bulk Density 1.6 1.7 1.3 1.8 1.7 1.5 1.1 1.6 1.5 1.0 0.9 (g/cc)^(c) Typ.Porosity 37 40 54 34 35 41 61 39 45 66 67 (%)^(c)

TGA/DTA analysis was performed on Sample 1. This sample showed a weightloss beginning at 125 C, wt. loss peak and exotherm at 277 C, and noapparent melting (to 1250 C/max T of run). In some embodiments,different fugitive phases are chosen, such that the burnout of thephases occurs at different temperatures.

Samples in Table 2 were subjected to the following firing cycles: FiringCycle #1: ramp 150 C/h to 550 C, hold at 550 C for 2 h, ramp 150 C/h to1050 C, hold at 1050 C for 0.5 h, cool at 200 C/h to room temperature;Firing Cycle #2: ramp 17 C/h to 93 C, hold at 93 C for 2 h, ramp 93 C/hto 500 C, hold at 500 C for 4 h; ramp 93 C/h to 800 C, hold at 800 C for2 h, ramp 150 C/h to 1050 C, hold at 1050 C for 0.5 h, cool at 150 C/hto room T; Firing cycle #3: ramp 17 C/h to 93 C, hold at 93 C for 2 h,ramp 93 C/h to 500 C, hold at 500 C for 4 h; ramp 93 C/h to 800 C, holdat 800 C for 2 h, ramp 150 C/h to 1050 C, hold at 1050 C for 5.0 h, coolat 150 C/h to room T. Fired samples were generally solid and strongenough for easy handling.

X-ray diffraction of Sample 1 after firing showed predominantly quartzand mullite, with smaller amounts of albite (calcian), possiblycristobalite, and hematite. Thermal expansion was measured between roomtemperature and 1000° C. at 3° C./minute (Linseis L75D/1550, Linseis,Inc., Robbinsville, N.J.) which yielded a CTE of approximately 5E-6/° C.

FIG. 13 shows two cross sectional electron micrographs of Sample 1 atdifferent magnifications. This example was a tubular body having adiameter of approximately 0.75 cm and wall thickness of approximately 1mm This sample displayed sufficient mechanical integrity for normalhandling operations typical of ceramic processing.

Porosity was measured using Hg porosimetry (Micromeritics Autopore IV9500, performed by Delta Labs, North Huntingdon, Pa.).

FIG. 14 shows pore size information associated with several exemplarybodies. This figure includes a vibrocast sample without an organicbinder and two extruded samples having organic binder. Sample 1 wasextruded using a high pressure, automated extruder. Sample 2 wasextruded using a hand extruder. Microstructure may be generallycontrolled with mixture composition, and a variety of forming methodsusable for forming bodies from particles may be used with variousembodiments. Some mixtures may be formable via several differentmethods.

FIG. 15 shows pore size information associated with several exemplarybodies. This figure compares bodies incorporating an extrinsic fugitivephase (added to an ash source) to bodies incorporating an intrinsicfugitive phase, associated with the ash source and generally resultingfrom a process that produced the ash particles (i.e., Sample 3). Samples3 and 7C had similar concentrations of different fugitive phases(intrinsic as ˜40% of the Pro-Ash High Carbon mass, vs. extrinsic Asbury4012). Porosity may be controlled via the use of one or many fugitivephases, which may include intrinsic and/or extrinsic fugitive phases,and may have similar and/or different particle sizes.

FIG. 16 shows pore size information associated with several exemplarybodies. This figure shows a range of pore size distributions that may becreated, according to various embodiments. Larger ranges, smallerranges, different pore size distributions and other properties maygenerally be created by suitable changes in processing parameters, andporosity and pore size distribution may generally be controlled. Poreconnectivity may be controlled using forming methods incorporatingvarious shear, compressive and tensile forces, and may also benefit fromthe use of anisotropic particles, particularly anisotropically shapedfugitive particles (e.g., whiskers, platelets).

FIG. 17 shows CPFT (cumulative percent finer than) data describing theporosity of several fired samples.

Table 3 summarizes porosity measurements for various samples.

TABLE 3 Median Pore Bulk Density Diameter at 0.52 psia Sample (micron) =(g/cc) % Porosity Baseline 3-35 1.8 1.81 33.6 2F 3-35+fineC 2.3 1.7035.3 3F 3-35+fineC 3.2 1.50 40.9 4F 3-35+fineC 6.4 1.07 61.2 6C3-35+coarseC 2.2 1.63 39.2 7C 3-35+coarseC 3.2 1.46 45 8C 3-35+coarseC11.8 1.00 65.8 8C+ 5 Hr. Soak 12.2 0.94 66.5 3-35-Extrude 2.0 1.62 37.43-35-LowPExtrude 2.1 1.71 39.7 3-ProAsh_HiC-Vibcast 3.7 1.29 53.8

FIG. 18 is a plot of average porosity vs. mean pore diameter for severalbodies, according to certain embodiments. Median pore diameter andpercentage porosity may be controlled independently. In someembodiments, an application vector may include a desired median porediameter and % porosity, and various samples are calculated/predictedand/or fabricated/measured, and various parameters are adjusted until abody vector associated with a resulting body sufficiently matches theapplication vector.

The above description is illustrative and not restrictive. Manyvariations of the invention will become apparent to those of skill inthe art upon review of this disclosure. The scope of the inventionshould, therefore, be determined not with reference to the abovedescription, but instead should be determined with reference to theappended claims along with their full scope of equivalents.

1. A method of making a porous body, the method comprising: selecting asource material and a fugitive phase; forming the selected sourcematerial and fugitive phase into a formed body; removing the fugitivephase from the formed body to yield a first porous body having a firstpore size distribution; treating the first porous body with a fluidcontaining particles that are filtered by the first porous body; andremoving the fluid to yield a second porous body having a second poresize distribution.
 2. The method of claim 1, wherein at least one of thesource material and the particles includes an ash source, and the secondporous body comprises greater than 10% of the ash source.
 3. The methodof claim 1, wherein the source material includes a first ash source andthe particles include a second ash source.
 4. The method of claim 1,further comprising firing at least one of the first and second porousbodies.
 5. The method of claim 1, wherein the source material ischaracterized by a first particle size distribution, the particles arecharacterized by a second particle size distribution, and the secondparticle size distribution has a smaller mean particle size than doesthe first particle size distribution.
 6. The method of claim 1, whereinthe fluid includes air.
 7. The method of claim 1, wherein the fluidincludes a gas.
 8. The method of claim 1, wherein at least one of thefirst and second porous bodies includes two or more regions havingdifferent porosities.
 9. The method of claim 1, wherein at least one ofthe source material and particles includes an ash source, and the secondporous body comprises more than 70% of the ash source.
 10. The method ofclaim 1, wherein at least a portion of the first porous body has greaterthan 60% porosity.
 11. The method of claim 1, wherein forming includessynthesizing a plurality of planar bodies and bonding the plurality ofplanar bodies together.
 12. The method of claim 11, wherein bondingincludes bonding the plurality of planar bodies using at least one of apaste and slip.
 13. The method of claim 1, wherein the source materialincludes a first ash source and a second ash source.
 14. The method ofclaim 13, wherein the first ash source is characterized by a first meanparticle size, the second ash source is characterized by a second meanparticle size, and the second mean particle size is between 5% and 25%of the first mean particle size.
 15. The method of claim 13, wherein thefirst porous body is comprised of between 50% and 90% of the first ashsource and between 10% and 50% of the second ash source.
 16. The methodof claim 1, wherein the source material includes an ash source havinggreater than 10% loss on ignition.
 17. The method of claim 1, whereinthe fugitive phase includes a solid, and removing the fugitive phaseincludes melting the fugitive phase.
 18. The method of claim 1, whereinthe fugitive phase includes ice.
 19. A porous body comprising more than40% of one or more ash sources.
 20. A method of treating a fluid, themethod comprising: providing a container having an inlet and an outlet;disposing a body within the container, the body comprising one or moreash sources; and causing a fluid to pass from the inlet to the outlet.